John
Lea
rned
at
Gat
linbu
rg 4
/05
Tracking in KamLAND?Tracking in KamLAND?
CAN WE USE OPTICS TO IMAGE TRACKS AND WHAT WOULD IT GET US?
John LearnedUniversity of Hawaii
At KamLAND Collaboration meeting
Gatlinburg, Tennessee, 4/05
Byron Dieterle has done optical studies, thought about problem,and been a great help in developing this idea.
John
Lea
rned
at
Gat
linbu
rg 4
/05
Basic Idea: a Scintillator “Bubble Chamber”
• If we can design the optics with enough
light collection
adequate depth of field• and not much rescattering of light
• Reconstruct tracks and precise vertices.Reconstruct tracks and precise vertices.
John
Lea
rned
at
Gat
linbu
rg 4
/05
KamLAND Physics ApplicationsKamLAND Physics Applications
• Accelerator neutrinos: superior recognition of electron events and rejection of πos.
• PDK: excellent K mode resolution.• SN: resolution of direction.• Reactors: better e+-n direction resolution.• Solar Nu’s: Some directionality.• Muons: very accurate track reconstruction,
increased rejection of backgrounds.• Nuclearites, Q-Balls, etc. : not presently
recorded in SK or KL (?)… opportunity.
John
Lea
rned
at
Gat
linbu
rg 4
/05
Sensitivity & ImplicationsSensitivity & Implications
• Aperture: assume 8 x 17”PMTs (~1.2m pupil)• Similar QE, efficiency• Assume 8 wide field cameras• ~2.4 PE/cm track in each camera• 40 MeV track yields ~200 pixels• 1 MeV yields ~10 pixels• Aim for resolution ~4 mm• Implies camera with ~4M pixels => commerically available CCDs
John
Lea
rned
at
Gat
linbu
rg 4
/05
Starting point: ASHRA Imaging Particle Detector
Pixel Cost Reduction by Pixel Cost Reduction by O(10O(1044))
Key TechnologyKey Technology
9M-pix. CMOS Sensor Covering 50deg-FoV9M-pix. CMOS Sensor Covering 50deg-FoV
PMT-array PMT-array CameraCamera
CMOS Sensor CMOS Sensor ChipChip
4,500x3,000 (14M) pix.
Commercial CMOS Camera
Ideas and leader: Makoto Sasaki, ICRR
John
Lea
rned
at
Gat
linbu
rg 4
/05
Design of Ashra Optics
F/0.74
Details can be found in
M.Sasaki et al, NIM A492 (2002) 49
• Schmidt-type optics• Spherical segment mirror• Spherical focal surface• 3-element corrector lens
Advantage: a large degree of freedom for optimization of lens surface shape to cancel1. spherical aberration2. chromatic aberration.
pupil : 1m
Modified Baker-Nunn
John
Lea
rned
at
Gat
linbu
rg 4
/05
Performance of Ashra Optics
wavelength
inci
den
t an
gle
4 largest peaks in air-fluorescence spectra
incidentangle
Spot diagram after optimization
John
Lea
rned
at
Gat
linbu
rg 4
/05
performance of Ashra Optics
Spot size = 0.0167°(1 arcmin)
using ZEMAX by A.Okumura
incidentangle
from weighted sum of several wavelength
Ashra Optics has capability to achieve 1 arcmin resolution
within the whole FOV of ± 25°
John
Lea
rned
at
Gat
linbu
rg 4
/05
3mφmirror3mφmirror1 deg/Pix1 deg/Pix
3mφmirror3mφmirror1 deg/Pix1 deg/Pix
3mφmirror3mφmirror1 deg/Pix1 deg/Pix
3mφmirror3mφmirror1 arcmin/Pix1 arcmin/Pix
3mφmirror3mφmirror1 deg/Pix1 deg/Pix
3mφmirror3mφmirror1 deg/Pix1 deg/Pix
3mφmirror3mφmirror1 deg/Pix1 deg/Pix
3mφmirror3mφmirror1 arcmin/Pix1 arcmin/Pix
What this does for ASHRAWhat this does for ASHRA EAS air fluorescence angular resolution EAS air fluorescence angular resolution
1arcmin1arcmin
ASHRAASHRAAngular ResolutionAngular Resolution
• < 1 arcmin at E > 1018.5eV
• 0.3 arcmin at E ~ 1020eV
John
Lea
rned
at
Gat
linbu
rg 4
/05
R&D R&D 状況ー状況ー 2/32/3 モデル望遠鏡モデル望遠鏡
• I.I.
• 補正レンズ• ミラー
2/3 scale prototype
John
Lea
rned
at
Gat
linbu
rg 4
/05
Image Intensifier Pipeline
• 46 Lp/mm => σ~7μm ~ CCD pix. size46 Lp/mm => σ~7μm ~ CCD pix. size• magnification factor = 1magnification factor = 1
• 4.6 Lp/mm =>σ~70μm @ input surface4.6 Lp/mm =>σ~70μm @ input surface• de-magnification factor de-magnification factor ~ ~ 1010
photocathode
photon
gate pulse >5ns
phosphor screen
Proximity focused I.I.
Focal sphere => => CMOS Sensor
Minimum modification of
focal surface
commercial ASHRA I.I.
Lens I.I.
Incident photons
John
Lea
rned
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Gat
linbu
rg 4
/05
Large Diameter Image Intensifier
Existing
16” (400mm)φphotocathode
photocathode resolution 3.4 line pair/mm
(largest and finest resolution in world)
24“ under development (but maybe 20” limit)
John
Lea
rned
at
Gat
linbu
rg 4
/05
Add Cameras to KamLAND?Add Cameras to KamLAND?
Would require drainingthe detector: stopper?
Present idea based onASHRA size camera.
Maybe smaller camera which replaces 1 PMTand requires no cutting steel, but then need More cameras.
John
Lea
rned
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Gat
linbu
rg 4
/05
Beam4 CalculationsBeam4 Calculations
• 9 surfaces sas16.opt
Diameter dia index Zvx Curv A4 A6 A8 shape Mir/Lens --------------:--------:----------:---------:----------------:------------------:---------------:--------------:---------:------------:• 2.400 : : : -.22 : -0.0 : 0. : 0. : 0. : 1. : lens : L1• 2.400 : : 1.414 : -.195 : -0.0013394: 0.07467649 : 0.0011911: 0. : 1. : lens : L1• 2.000 : : : -.05 : 0.0130258:-0.06570667 :-0.0011347:-0.000453 : 1. : lens : L2• 2.000 : : 1.414 : 0.0 : -0.0 : 0. : 0. : 0. : : iris : L2
2.000 : : 1.414 : .05 : -0.0130258: 0.06570667 : 0.0011347: 0.000453 : 1. : lens : L2 2.400 : : : .195 : 0.0013394:-0.07467649 :-0.0011911: 0. : 1. : lens : L3
• 2.400 : : 1.414 : .22 : -0.0 : 0. : 0. : 0. : 1. : lens : L3• 2.400 : : :1.50 :-.667 : : : : 1. : mirror : M• 0.400 : : :0.694 :-1.441 : : : : 1. : other : D
Simple setup, easy to get started Start with Sasaki design
Can do simple optimization
Example of card file below:
Calculations by Byron Dieterle
John
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/05
Byron has done some Beam4 Sims for KL-like GeometryByron has done some Beam4 Sims for KL-like Geometry
Conclude: resolutions of order of mm are achieved at IIT.Conclude: resolutions of order of mm are achieved at IIT.
John
Lea
rned
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Gat
linbu
rg 4
/05
Image of a Track
Use tomographic methods to reconstructout of focus image.
John
Lea
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/05
ConclusionConclusion
• Idea to add imaging to KamLAND needs study…. optics, design practicality, sensitivity, reconstruction.
• How about small camera in place of a neck 6” PMT? Could do muon tracks, nuclearites?
• Biggest question: does it buy us something really important?
• Should we pursue it? Anyone interested?